This invention relates generally to automatic controls for prime mover steering systems, and more particularly concerns an automatic steering system for a device such as a farm tractor.
In operating a prime mover such as a farm tractor in a field, the operator faces the tedious and tiring task of accurately guiding the prime mover and any pulled or operated implements with great precision along a predetermined path. For example, in plowing it is necessary to steer the pulling farm tractor so that evenly spaced furrows are created adjacent those furrows created in the last plow pass. The careful attention of the plowman is required in steering the tractor, yet he must also attend to adjusting tractor speed, plow depth and other variables.
To reduce this burden on the prime mover operator, a number of automatic steering devices have been offered to assist in tractor steering or to take over these steering jobs entirely. Until the present time, however, these devices have been more numerous than successful, and it is still the common practice to use manual steering methods to steer farm tractors while plowing, seeding, cultivating or otherwise treating field crops. It has been a major problem with automatic steering devices to date that once the automatic steering device is put into operation there is no means to manually override the automatic device with the conventional steering mechanism.
It is accordingly a general object of the present invention to provide a commercially attractive automatic steering mechanism for a prime mover such as a farm tractor.
An object of the present invention is to provide an automatic steering device which may be manually overridden by conventional steering apparatus.
Another object of the present invention is to provide a clutch mechanism for the above identified type of automatic steering device which holds a conventional steering mechanism in engagement with an automatic steering mechanism during small displacements of the conventional steering mechanism such as when the automatic steering device is effectively operative; and the clutch mechanism is operative to disengage the conventional steering mechanism when large displacements of the conventional steering mechanism occur for the purposes of preventing damage to the automatic steering mechanism and allowing an operator to override the automatic steering mechanism with the conventional steering mechanism when necessary.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.